The present invention broadly relates to a pressurizing type image recording apparatus in which an image carried by a photo- and pressure-sensitive material is transferred to an image receiving material as the photo-sensitive material is superposed on and pressed to the image receiving material.
More particularly, the invention is concerned with an image recording apparatus which makes use of a photo- and pressure-sensitive material having a substrate and a layer of a substance on the substrate, the substance being photo-sensitive and, not exclusively, developable by application of heat, the substance further being capable of fixing the developed image by application of a pressure, the heat-developable material after exposure and development being superposed on and pressed to an image receiving material, whereby an image is received by the image receiving material.
An image recording material employing microcapsules containing a photosensitive composition is known. An example of such a recording material is disclosed in Japanese Patent Laid-open No. 179,836/1982. This recording material has a substrate which carries capsules made of a synthetic polymeric resin and containing a vinyl compound, a photopolymerization initiator and a coloring precursor.
In recording an image using this recording material, the material is first exposed so that the microcapsules are hardened in conformity with the form of the image. Then, as the recording material is pressed, the microcapsules which have not been hardened are ruptured so as to release the coloring agent precursor, thus forming a color image. This image recording system provides a high quality of the recorded image with a dry-type simple processing, but suffers from a disadvantage in that the photosensitivity is much smaller as compared with the system which makes use of silver halide.
Under this circumstance, the present applicant has proposed, in the specification of Japanese Patent Application No. 117089/1985, a novel recording material which has a high photosensitivity and which ensured a high quality of the recorded image with a simple dry-type process. This recording material is a photo- and pressure-sensitive heat-developable material constituted by a carrier and a layer formed on the surface of the carrier, the layer containing at least a photosensitive silver halide, reducing agent, polymerizable compound and a color image forming substance, wherein the polymerizable compound and the color image forming substance are confined in common microcapsules.
An image recording method which makes use of this photo- and pressure-sensitive heat-developable material is disclosed in the specification of Japanese Patent Application No. 121284/1985 filed by the same applicant. According to this method, the heat-developable material is first exposed so that a latent image is formed thereon in conformity with the image to be recorded. Then, the material is heated for development so that the polymerizable compound in the area where the latent image exists is polymerized to produce a polymeric compound, thus thermally setting the microcapsules. Then, the material is superposed on an image receiving material having an image receiving layer capable of receiving the color image forming substance, and is pressed to the image receiving material so that at least part of the microcapsules having no latent image is ruptured so as to transfer the color image forming substance to the image receiving material, thereby forming an image on the latter.
In order to obtain a clear image by the transfer of the heat-developed image from the photo- and pressure-sensitive heat-developable material to the image receiving material, it is essential that the heat-developable material be pressed uniformly onto the image receiving material under a given condition.
A pressure-fixing device used in the field of electrophotography is known as an apparatus which is capable of uniformly pressurizing a sheet material. This device is a compact device having a pair of pressurizing rolls which are pressed to each other such that their axes form a predetermined angle .alpha. therebetween, so that the sheet material which passes through the nip between these rollers can be uniformly pressed at a high pressure. This device, however, produces a problem when it is used for the pressure-transfer of the image from the heat-developable material to the image receiving material. Namely, when two sheets, i.e., the heat-developable material and the image receiving material, are made to pass through the nip between two pressurizing rollers, these two sheets are driven in different directions because these rollers are arranged at an inclination to each other, so that two sheets tend to be offset from each other with the result that the transferred image is distorted or the sheets are wrinkled.
Another problem encountered is that there has been proposed no image recording apparatus of the kind described which is capable of performing automatically a series of operations including exposure of the heat-developable material, superposition of the heat-developable material and image receiving sheet, transfer by pressurizing and formation of the image on the image receiving material, while ensuring economical supply of the heat-developable and image receiving materials and avoiding any jamming of the materials in the apparatus, with compact design of the apparatus having no substantial projection from the apparatus body.
Still another problem encountered by the prior art is that there has been proposed no image recording apparatus of the kind described which is capable of performing automatically a series of operations including exposure of the heat-developable material, superposition of the heat-developable material and image receiving sheet, transfer by pressurizing and formation of the image on the image receiving material, while enabling an easy administration of the photosensitive material and avoiding any winding or rolling tendency of the photosensitive material, thus assuring highly precise transfer of the image and, hence, a high quality of the recorded image.
Accordingly, a first object of the present invention is to provide an image recording apparatus of the type described, wherein the photo- and pressure-sensitive heat-developable material and the image receiving material, which are superposed one on the other, can be uniformly pressurized at a pressure which is easily adjustable, without being accompanied by problems such as distortion of the transferred image and wrinkling of both sheet materials.
To this end, according to one aspect of the present invention, there is provided an image recording apparatus which employs a photo- and pressure-sensitive heat-developable material having a substrate and a layer formed on the substrate from a material which is photo-sensitive and heat-developable and which enables the developed image to be fixed by a pressure, and an image receiving material, the heat-developable material and the image receiving material being adapted to be superposed one on the other and pressed to each other so as to transfer the image from the heat-developable material to the image receiving material, the apparatus comprising: a pair of pressing rolls for nipping the heat-developable material and the image receiving material therebetween; back-up rolls means having an axial length smaller than that of the pressing rolls and adapted for acting on at least one of the pressing rolls; and back-up roll pressing means capable of independently adjusting the pressure exerted by the back-up roll means on the pressing rolls.
A second object of the present invention is to provide a compact construction of image recording apparatus in which the portions such as those accommodating the heat-developable material and image receiving material do not project from the apparatus body, and in which the risk for the heat-developable material and the image receiving material to be jammed in the apparatus is minimized.
To this end, according to another aspect of the present invention, there is provided an image recording apparatus which employs a photosensitive material having a substrate and a layer formed on the substrate from a material which enables the developed image to be fixed by a pressure, and an image receiving material, the photosensitive material and the image receiving material being adapted to be superposed one on the other and pressed to each other so as to transfer the image from the photosensitive material to the image receiving material, the apparatus characterized in that the photosensitive material and the image receiving materials are supplied from rolls of the respective materials.
The term "photosensitive material" in this case is used to represent any material capable of transferring an exposure image to an image receiving material having an image receiving layer, by application of pressure. An example of such a material is the one which is disclosed in Japanese Patent Laid-open No. 179,836 mentioned before.
The photosensitive material may be of the type which is heat-developed or wet-developed in advance of the transfer by application of pressure. As an example of such a material, the specification of Japanese Patent Application No. 121,284 mentioned before discloses a material composed of a substrate and a layer formed on the substrate from at least a photosensitive silver halide, polymerizable compound and a color image forming substance, wherein at least the polymerizable compound and the color image forming material are charged in common capsules. When this material is used, the photosensitive material is exposed and the latent image formed by the silver halide is developed by heat-development simultaneously with the thermal setting of the polymerizable compound. Then, the pressure is applied to visualize the image.
A third object of the invention is to provide an image recording apparatus in which the photosensitive material is supplied in the form of separate sheets so that any tendency of fogging which tends to appear when the photosensitive material is rolled can be effectively suppressed and the construction of the device for supplying the photosensitive material is simplified.
It is also an object of the invention to provide an image recording apparatus in which the photosensitive material does not exhibit any winding or rolling tendency so as to suppress occurrence of jamming and to ensure a close contact with the image receiving material, thus assuring a high prevision of transfer and, hence, a high quality of the recorded image.
It is also an object of the invention to provide an image recording apparatus in which the photosensitive material is interchangeable for a variety of photosensitivity levels, sizes and other conditions.
It is also an object of the invention in which the image receiving material is supplied from a roll, so that the portions projecting from the body of the apparatus is decreased, thus allowing an easy handling of the apparatus.
To these ends, according to still another aspect of the present invention, there is provided an image recording apparatus which employs a photosensitive material having a substrate and a layer formed on the substrate from a material which enables the developed image to be fixed by a pressure, and an image receiving material, the photosensitive material and the image receiving material being adapted to be superposed one on the other and pressed to each other so as to transfer the image from the photosensitive material to the image receiving material, the apparatus characterized in that the photosensitive material is supplied in the form of separate sheets while the image receiving materials is supplied from a roll of the image receiving material.
A fourth object of the present invention is to provide an image recording apparatus in which the photosensitive material and the image receiving material are supplied by devices having simple constructions.
It is also an object of the present invention to provide an image recording apparatus in which the photosensitive material and the image receiving material fed to the apparatus do not have any rolling tendency so that they are superposed in close contact with each other thus assuring a high transfer precision and, hence, high quality of the recorded image.
It is also an object of the present invention to provide an image recording apparatus in which both the photosensitive material and the image receiving material are changeable for a variety of sensitivity levels, sizes and kinds of materials, e.g., ordinary image receiving paper or transparency sheet for overhead projectors.
To these ends, according to a further aspect of the invention, there is provided an image recording apparatus which employs a photosensitive material having a substrate and a layer formed on the substrate from a material which enables the developed image to be fixed by a pressure, and an image receiving material, the photosensitive material and the image receiving material being adapted to be superposed one on the other and pressed to each other so as to transfer the image from the photosensitive material to the image receiving material, the apparatus characterized in that the photosensitive material and the image receiving materials are supplied, respectively, in the form of separate sheets.